Chapter 2: Installation, Page 15
M o d e l 6 8 2 T - H P U S E R M A N U A L A T E X Z o n e 2
2.4 Purge Startup Procedure
The AMETEK ASOMA Model 682T-HP, ATEX Zone 2 configuration uses an Expo Model 07/ZLC/bp/IS
purge unit to achieve enclosure protection. While this system does not automatically control power to the
analyzer (as with an X-purge system), it will trigger an alarm and alert the user upon loss of protective pressure.
The Z-Purge system has been set and tested at the factory, but it is still a good idea to make sure the purge
system is functional before turning on power to the analyzer.
The operating instructions for the Expo Model 07/ZLC/bp/IS purge unit are included here from the Expo
Operation Manual (assume the enclosure is sealed – PE stands for Pressurized Enclosure):
1.
Open the supply shutoff valve.
2.
Adjust the Leakage Compensation Valve (LCV) so that the enclosure pressure
rises to the point where the “Pressurized” indicator turns green.
3.
Continue to raise the PE pressure until the Relief Valve (RLV) opens. Check
that the RLV opens at or below (4.0 inches wc).
4.
Lower the PE pressure until the “Pressurized” indicator turns red. Check that
the indicator turns red at or above (0.2 inches wc).
5.
Open the LCV again and set the PE pressure to a level around 50% of the RLV
operating pressures. This “working” pressure is not critical. The
“Pressurized” indicator should be green.
6.
Turn the Purge Control Valve “On”. This will start the High Purge Flow and
the “Purging” indicator should turn amber. If the “Purging” indicator
remains black the flow through the outlet valve is below the minimum for
which the Flow Sensor has been calibrated. Check the air supply pressure at
the inlet to the Control Unit while purging is taking place. It must be above
(60 psi). If the supply pressure is correct and the “Purging” indicator does not
turn amber, there is too much leakage from the PE. Find and fix the leaks
.
“Purging” does not start until the indicator turns amber.
7.
…The user must ensure that the time delay between the indicator turning
amber and the application of power to the PE
is not less than the minimum
time required to purge the PE as shown on the model 682T nameplate.
Never
turn on the power without purging first unless you have proved that the
interior of the PE is gas free and checked that the “Pressurized” indicator
is green!
After the purge time is completed the Purging Valve should be turned “Off”. The
High Purge Flow will cease and the air flow into the enclosure will then be
controlled once again by the (LCV). It should now be re-adjusted if necessary. The
RLV should be closed and the enclosure pressure around 50% of the RLV opening
pressure…the user must (apply power to the PE) only after the enclosure has been
pressurized and purged sufficiently to ensure that the interior of the enclosure is
(flammable) gas free. The power should be shut off as soon as possible after
pressure failure. This is also the user’s responsibility.
Summary of Contents for 682T-HP
Page 1: ...Model 682T HP Sulfur Analyzer ATEX Zone 2 pzc User Manual 9000 223 VE REV C...
Page 25: ...Chapter 3 Operation Page 18 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 56: ...Chapter 5 Hardware Details Page 49 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 66: ...Chapter 5 Hardware Details Page 59 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 67: ...Chapter 5 Hardware Details Page 60 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 70: ...Chapter 5 Hardware Details Page 63 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 72: ...Chapter 5 Hardware Details Page 65 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 75: ...Chapter 5 Hardware Details Page 68 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
Page 76: ...Chapter 5 Hardware Details Page 69 M o d e l 6 8 2 T H P U S E R M A N U A L A T E X Z o n e 2...
